1. Get an adequately sized tank. I wouldn't recommend putting them together, unless I knew the newt species.
2. Fill the bottom of the tank with gravel, making a steep "hill".
3. Fill it with an inch of water, keeping part of the "hill" sticking out.
4. Get a branch/bird perch for a "dry" area.
5. Feed them "vitamin loaded" crickets about 3-4 days a week.
6. Clean the tank about 3+ times a week
*Another tank setup is dry, with a filled water dish for a wet area.